TW201518816A - Backlight module - Google Patents

Abstract

A backlight module includes an optical film group, a light source board and a number of LEDs positioned on the light source board. The backlight module further includes a reflection frame positioned between the optical film group and the light source board. The reflection frame includes an upper frame, a lower frame and a reflection board positioned between the upper frame and the lower frame. The upper frame defines a receiving portion for accommodating the optical film group. The lower frame is connected with the light source board. There are a number of light holes defined on the reflection board. The reflection board, the lower frame, and the light source board cooperatively form a sealed space. The backlight module of the present invention has a reflection frame positioned between the optical film group and the light source board, therefore a thinner backlight module is provided and the light output thereof can be uniform.

Description

Backlight module

The invention relates to a backlight module, in particular to a direct type backlight module.

Since the liquid crystal panel of the liquid crystal display device cannot emit light, it is necessary to provide a light source by the backlight module to realize image display of the liquid crystal panel. However, with the continuous rapid development of liquid crystal display devices, backlight modules used in liquid crystal display devices are increasingly required to be thinner.

Traditionally, an edge-lit backlight module has been used to solve the problem of thinning the backlight module. However, the light source of the edge-lit backlight module can only be disposed on the side of the light guide plate, which is limited by the number of light source settings. . At the same time, the edge-lit backlight module uses a light guide plate to cause a certain amount of absorption loss during the propagation of the light, so that the edge-lit backlight module cannot provide a higher luminous flux.

A conventional direct type backlight module includes an optical film, a diffusion plate, a light guide plate, and a light source. The optical film is disposed on the diffusing plate, and the diffusing plate is disposed on the light source and is separated from the light source by a light mixing distance. However, the light mixing distance between the light source and the diffuser plate needs to be large enough to ensure uniform brightness of the entire backlight as viewed from above the optical film. If the backlight module is thicker, it is not conducive to thin design.

In view of this, it is necessary to provide a backlight module that is thin and uniform in light output.

A backlight module includes an optical film set, a light source substrate, and a plurality of LED light sources disposed on the light source substrate. A reflective frame body is further disposed between the optical film set and the light source substrate, and the reflective frame body comprises an upper frame, a lower frame and a reflective plate disposed between the upper frame and the lower frame, and the upper frame is provided with an optical film group. The lower frame is connected to the light source substrate; the reflective plate is provided with a plurality of transparent holes; the reflective plate, the lower frame and the light source substrate form a closed cavity.

The backlight module can effectively transmit and reflect light through the reflective plate of the perforated plate structure, replacing the traditional light guide plate, and increasing the light utilization efficiency. The optical die set is received on the upper frame of the reflective frame, and a small light mixing gap is maintained between the optical die set and the reflective plate, which not only enhances the uniformity of the light output and the brightness of the light, but also contributes to the thinning of the backlight module. the design of.

1 is an exploded perspective view of a backlight module according to Embodiment 1 of the present invention.

2 is a cross-sectional view of the backlight module shown in FIG. 1.

3 is a partial enlarged view of the backlight module shown in FIG. 2.

4 is a top plan view of a backlight module according to Embodiment 1 of the present invention.

FIG. 5 is an exploded perspective view of a backlight module according to Embodiment 2 of the present invention.

The backlight module provided by the present invention will be further described in detail below with reference to the drawings and embodiments.

Referring to FIG. 1 , a backlight module 100 according to a first embodiment of the present invention is disposed under a liquid crystal panel (not shown), and includes an optical film set 110 , a reflective frame 120 , a light source substrate 140 , and a light source substrate 140 . The plurality of LED light sources 130 are on.

The optical film set 110 includes a plurality of optical sheets. Preferably, the plurality of optical sheets are a diffusion sheet 111, a prism sheet 112, a prism sheet 113, and a diffusion sheet 114 which are laminated.

The reflective frame 120 is made of a plastic material and is integrally formed. The reflection frame 120 includes an upper frame 121, a reflection plate 122, and a lower frame 123. The reflection plate 122 is located at a central portion of the reflection frame 120.

Referring to FIG. 2 and FIG. 3 together, the upper frame 121 is a rectangular frame that opens in the direction of the optical film, and the liquid crystal panel housing portion 1211 and the optical film group storage portion 1212 are opened on the side wall of the upper frame 121. The liquid crystal panel accommodating portion 1211 and the optical film group accommodating portion 1212 are both stepped, wherein the lower bottom surface of the liquid crystal panel accommodating portion 1211 provides a function of supporting the liquid crystal panel, and the side surface of the liquid crystal panel accommodating portion 1211 provides a function of holding and fixing the liquid crystal panel. . The optical film group accommodating portion 1212 is for accommodating and holding the optical film group 110. It can be understood that the liquid crystal panel housing portion 1211 and the optical film group storage portion 1212 may have other shapes as long as they are convenient for accommodating the liquid crystal panel and the optical film group.

The bottom surface of the optical film group accommodating portion 1212 is higher than the reflection plate 122, so that a light mixing gap D is formed between the optical film group 10 and the reflection plate 122 housed in the optical film group accommodating portion 1212, and the optical film group 110 and the reflection are formed. The plate 122 and the upper frame 121 enclose a closed mixing cavity 1213 to enhance the uniformity of light exiting the optical film set 110.

The reflection plate 122 is provided with a plurality of light transmission holes 1221 for transmitting the light emitted by the LED light source 130 and the light reflected between the light source substrate 140 and the reflection plate 122. The light transmission hole 1221 may be a circular hole or a square hole, but is not limited thereto. Preferably, the light transmission holes 1221 are arranged in an array. The reflecting plate 122 is provided with a reflective layer having a high reflectance toward the surface of the light source substrate 140 and the surface facing the optical film group 110.

Referring to FIG. 2 and FIG. 4 together, in order to evenly distribute the light emitted from each position, the aperture ratio per unit area of the light transmission hole 1221 increases as the distance from the LED light source 130 increases. In the present embodiment, the distribution density of the light transmission holes 1221 is uniform. However, the diameter of the light hole of the light transmission hole 1221 is larger as the distance from the LED light source 130 is larger. It can be understood that the embodiment is not limited to the above one mode. The diameter of the light holes of the light-transmitting holes may be the same, but the distribution density of the light-transmitting holes is larger as the distance from the LED light source 130 is larger.

The lower frame 123 is a rectangular frame structure that is open toward one side of the light source substrate 140, wherein the inner side wall of the lower frame 123 is a reflective surface having high reflectivity. It can be understood that the inner side wall of the lower frame 123 can also be attached with a reflective layer with high reflectivity. The structure of the lower frame 123 having the inner wall with high reflectivity can reduce the loss of light, so that the light emitted by the LED light source 130 is highly efficient. The form is formed by the light transmission hole 1221. At the same time, the rectangular opening of the lower frame 123 is connected to the rectangular edge of the light source substrate 140.

Referring to FIG. 3 and FIG. 4 together, the plurality of LED light sources 130 are evenly arranged in an array on the light source substrate 140 for providing the light source of the backlight module 100.

The light source substrate 140 has a high reflectivity toward one side of the reflecting plate 122. Further, the light source substrate 140, the lower frame 123 and the reflecting plate 122 collectively form a closed cavity 1231. The sealed cavity 1231 causes the light emitted from the plurality of LED light sources 130 to be mixed, and causes the light to exit from the light transmission hole 1221 on the reflection plate 122. The invention achieves the effect of mixing light by the closed cavity 1231, and can replace the light guide plate in the conventional light guiding module, so that the backlight module is lighter and thinner.

In addition, the plurality of LED light sources 130 of the present invention are evenly arranged in the array in the backlight module 100, and the switching state of each LED light source 130 can be independently controlled by providing an independent driving circuit, so that the backlight module of the present invention 100 has a function of partial lighting. As shown in FIG. 4, when only the LED light source 130 in the first region 131 and the second region 132 is turned on, only the liquid crystal display panel corresponding to the first region 131 and the second region 132 is illuminated.

When the backlight module 100 is assembled, the diffusion sheet 111, the prism sheet 112, the prism sheet 113, and the diffusion sheet 114 of the optical film group 110 are sequentially stacked from top to bottom. Then, the optical film group 110 is placed in the optical film group housing portion 1212 of the reflection frame 120, and the liquid crystal panel is placed in the liquid crystal panel housing portion 1211 of the reflection frame 120, and the lower portion of the reflection frame 120 is placed. A rectangular opening portion below the frame 123 is connected to the rectangular rim of the light source substrate 140.

Referring to FIG. 2 and FIG. 3 again, the light propagation path of the backlight module 100 is: the plurality of LED light sources 130 diverge light to the periphery, wherein a small portion of the light is directly transmitted through the light transmission hole 1221, and other light is irradiated to the reflection. The reflective layer of the plate 122 is totally reflected by the reflective layer of the reflective plate 122, and then reflected by the inner surface of the light source substrate 140 having high reflectivity, and reflected by the loop, finally making the light into a high density small. The beam light is emitted from the light transmission hole 1221. The high-density beam light is further illuminating the optical film group 110 more uniformly by the light mixing effect of the light mixing cavity 1213, and the loss of the light propagation process is reduced due to the high reflectivity property of the reflective layer. Increased light utilization, which enhances brightness.

The reflective frame 120 is an integrally formed multi-functional structure, and not only the liquid crystal panel housing portion 1211 and the optical film group housing portion 1212 are provided, but also the reflective plate 122 in the middle of the reflective frame 120 is provided with a light-transmitting hole 1221 to form a uniform output. Shoot light. Therefore, the backlight module 100 has the advantages of simple structure and easy assembly.

The backlight module 100 provided by the present invention can replace the light guide plate in the conventional light guide module by using the sealed cavity 1231 to make the backlight module lighter and thinner. Further, since the bottom surface of the optical film group housing portion 1212 is raised above the reflection plate 122, the light mixing gap D formed between the optical film group 110 and the reflection plate 122 is formed. On the premise that the optical film group 110 and the reflection plate 122 are not attached, the light mixing gap D is greater than or equal to 0.2 mm. The design of the backlight module 100 is effectively enhanced. At the same time, since the reflective plate 122 is provided with an array of light-transmissive holes 1221, the backlight module 100 also has a uniform light-emitting effect. Moreover, the independent driving circuit can independently control the switching state of the corresponding LED light source 130 of the plurality of LED light sources 130, so that the backlight module 100 of the present invention further has the function of partial lighting.

Referring to FIG. 5 , the backlight module 200 of the second embodiment of the present invention is similar to the backlight module 100 of the first embodiment. The backlight module 200 includes an optical film set 210 , a reflective frame 220 , an LED light source 230 , and a light source substrate . 240. The backlight module 200 is different from the backlight module 100 in that the material of the upper frame 221 of the backlight module 200 is made of plastic material, and the reflection plate 222 and the lower frame 223 are integrally formed of a high-reflectivity metal sheet material. The backlight module 200 can also achieve the effects of thinning and uniform light emission.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

100, 200‧‧‧ backlight module

110, 210‧‧‧ Optical film set

111‧‧‧Diffuser

112‧‧ ‧ prism sheet

113‧‧ ‧ prism sheet

114‧‧‧Diffuser

120, 220‧‧‧reflective frame

121, 221‧‧‧ upper box

1211‧‧‧LCD panel storage unit

1212‧‧‧Optical diaphragm group storage unit

1213‧‧‧Hybrid cavity

122, 222‧‧‧ reflection plate

1221‧‧‧Light hole

123, 223‧‧‧ lower box

1231‧‧‧Closed cavity

130, 230‧‧‧LED light source

131‧‧‧First area

132‧‧‧Second area

140, 240‧‧‧Light source substrate

no

100‧‧‧Backlight module

110‧‧‧Optical diaphragm group

111‧‧‧Diffuser

112‧‧ ‧ prism sheet

113‧‧ ‧ prism sheet

114‧‧‧Diffuser

120‧‧‧Reflecting frame

121‧‧‧上框

122‧‧‧reflector

1221‧‧‧Light hole

123‧‧‧ Lower frame

130‧‧‧LED light source

140‧‧‧Light source substrate

Claims (9)

A backlight module includes an optical film set, a light source substrate, and a plurality of LED light sources disposed on the light source substrate, wherein the optical film set and the light source substrate are further provided with a reflective frame, and the reflection The frame body includes an upper frame, a lower frame, and a reflective plate disposed between the upper frame and the lower frame, wherein the upper frame is provided with an optical film group accommodating portion, and the lower frame is connected to the light source substrate; The plate is provided with a plurality of transparent holes; the reflector, the lower frame and the light source substrate form a closed cavity. The backlight module of claim 1, wherein an aperture ratio per unit area of the light transmission hole increases as a distance from a corresponding LED light source increases. The backlight module of claim 1, wherein the reflective frame upper frame further comprises a liquid crystal panel receiving portion for receiving the liquid crystal panel. The backlight module of claim 1, wherein the light source substrate has a reflective layer with high reflectivity toward one side of the reflector. The backlight module of claim 1, wherein a light mixing gap between the reflector and the optical sheet is greater than or equal to 0.2 mm. The backlight module of claim 1, wherein the reflective frame is made of a high reflectivity plastic material. The backlight module of claim 1, wherein the reflector and the lower frame are made of a metal thin plate having a high reflectivity on the surface. The backlight module of claim 1, wherein the upper frame is made of a plastic material. The backlight module of claim 1, wherein the optical film set comprises a diffusion sheet, a prism sheet, a prism sheet and a diffusion sheet which are laminated.